Rheem R802VA07542117MSA Error Code *T055_F: Inducer Hi Pressure Switch Won't Open (Two-Stage Only)

What Does Code *T055_F Mean?

Because your R802VA07542117MSA is a two-stage, variable-speed furnace, Rheem gives it two separate inducer pressure switches: a low-stage switch for normal low-fire draft and a high-stage switch that proves the stronger draft of high fire. Code T055_F applies specifically to two-stage operation and involves that high-stage switch. It is logged when the Bluetooth Communicating IFC (Integrated Furnace Control) finds the high-stage pressure switch still CLOSED at a point in the cycle when it should be OPEN, so the control cannot confirm the switch changes state correctly. A single-stage furnace has no high-stage switch and never sees this code.

The key to T055_F is that it is a "won't open" fault, which is the opposite of a "won't close" fault. "Won't open" means the switch is stuck closed when it should be open, which typically indicates a switch with welded contacts or a jammed diaphragm, or a sensing hose that is trapping pressure and holding the switch closed. That is fundamentally different from code T057_F, the high-stage "won't close" fault, where the inducer is running at high fire but cannot build enough draft to close the switch, usually because of a blocked vent.

That distinction is why T055_F is not a homeowner venting-clearing job. Clearing the outdoor vent termination helps a switch that cannot close, but it does nothing for a switch that is stuck closed. T055_F also has a direct sibling on this board: code A055_F is the alarm-level, persistent counterpart of the same high-stage "won't open" condition. The T (troubleshooting) prefix here means the control saw the fault, whereas the A (alarm) prefix on A055_F means it has persisted. Correcting T055_F means replacing the high-stage pressure switch or fixing its hose, which is technician work on a safety that proves the furnace vents properly at high fire.

What You'll Notice

• The furnace runs on low heat but faults or will not step up when high fire is demanded
• The furnace struggles to reach full heat output on the coldest days
• The alphanumeric LED blinks "T055_F" one digit at a time with a roughly three-second pause between digits
• The fault appears around the transition to high stage rather than at low-fire startup
• Resetting the furnace does not clear the condition when high fire is called again

Common Causes

How This Is Diagnosed

A technician treats T055_F as a "stuck closed" condition on the high-stage switch rather than a draft problem, so the outdoor vent is not the focus. The technician measures the high-stage pressure switch contacts to see whether they are electrically closed when they should be open, which indicates welded contacts or a jammed diaphragm.

If the switch checks out, the technician inspects its sensing hose for a kink, moisture, or debris that could trap residual pressure and hold the switch closed. Because this is a two-stage-only fault, the technician also confirms that a correct high-stage switch for this model is installed if the fault recurs after a replacement.

When to Call a Professional

This code involves components that are not homeowner-serviceable, so have a licensed HVAC technician diagnose and repair it. Keep in mind:

• The furnace only runs on low heat and will not step up to high fire
• T055_F remains after the furnace has been reset several times
• The high-stage pressure switch or its sensing hose is suspected of trapping pressure or moisture
• The fault has also escalated to the alarm-level code A055_F
• You smell gas or exhaust odor anywhere near the furnace or vent piping

✓ Verified against manufacturer service manual — March 2026